Leptospira bacteria detected in rodents in Tana River and Garissa counties of Kenya

Figures & data

Figure 1. Map of Kenya and the two study areas, Tana River and Garissa Counties, with towns involved in the study highlighted.

Figure 2. The phylogenetic analysis was performed on isolates from both study counties (highlighted with black dots) and compared with sequences of the secY gene of known leptospiral species. The evolutionary history was infered using the Maximum Likelihood method based on the Tamura-Nei model [26]. The tree with the highest log likelihood (−1108.1041) is shown. The percentage of trees in which the associated taxa clustered together is shown next to the branches.

Table 1. Distribution of rodents collected with the towns and diagnostic test results in the study sites.

	Bura			Hola			Ijara			Sangailu			Total
Species	Total	PCR	ELISA	Total	PCR	ELISA	Total	PCR	ELISA	Total	PCR	ELISA	Total	PCR	ELISA
Acomys wilsoni	0			7	NT	NT	1	1/1 100%	0/1 0%	0			8	1/1 100%	0/1 0%
Arvicanthis niloticus	1	NT	NT	0			0			0			1	NT	NT
Gerbilluscus robustus	0			0			1	1/1 100%	0/1 0%	0			1	1/1 100%	0/1 0%
Mastomys natalensis	18	2/13 15.4%	8/13 61.5%	3	2/2 100%	0/2 0%	1	1/1 100%	1/1 100%	11	4/5 80%	1/1 100%	33	9/21 42.9%	10/17 58.8%
Mus musculus	26	2/12 16.7%	1/12 8.3%	27	4/15 26.7%	2/13 15.4%	11	6/8 75%	0/5 0%	10	3/7 42.9%	1/5 20%	74	15/42 35.7%	4/35 11.4%
Rattus rattus	0			2	2/2 100%	0/2 0%	0			0			2	2/2 100%	0/2 0%
Total	45	4/25 16%	9/25 36%	39	8/19 42.1%	2/17 11.8%	14	9/11 81.8%	1/8 12.5%	21	7/12 58.3%	2/6 33.3%	119	28/67 41.8%	14/56 25.0%

NT = not tested.

Table 2. Summary findings of focus group discussion of the perceptions of human diseases and wildlife in the community.

Period	Perceptions about important wildlife and the environment	Perceptions of most definitive illnesses in the communities
1961	Lots of wild animals (big game) including big cats, wild dogs and elephants	Non-severe malaria, bilharzia, typhoid and few cases of blood pressure
1970–1980	Big mammals were many but reducing (elephants were not seen)	Diarrhoea, measles, chicken pox, trypanosomiasis/sleeping sickness
1982–1987	Some big game (zebras, big gazelles, hyenas and wild pigs). Increase in rat numbers noted	Malaria, typhoid, dehydration, HIV/AIDS, ulcers, blood pressure, pesticide poisoning (directly and indirectly)
1988–1989	Collapse of the irrigation schemes, reduced number of big game and other wild animals except baboons, wild pigs, porcupines, squirrels. Introduction of the Mathenge weed (Prosopis juliflora)	Malaria, typhoid, dehydration, HIV/AIDS, ulcers, high blood pressure, pesticides poisoning (directly and indirectly)
From the 1990s	Expansion of Prosopis juliflora	Malaria, pneumonia, high blood pressure, typhoid, diabetes, chicken pox, sleeping sickness, bilharzia, HIV/AIDS, tuberculosis, fungal infections, livestock diseases and deaths
2000	Increase in big rats, squirrels, re-emergence of lions, caracal	Malaria, stomach illnesses, dehydration, anaemia, malnutrition
2003-onwards	Mathenge (Prosopis juliflora) forests, revival of the irrigation schemes, increase in rodents	Amoebasis, typhoid fever, cancer, malaria, bilharzia, HIV/AIDS, asthma

Table 3. Rodent samples from Garissa and Tana river county tested for Leptospira spp. using both ELISA and PCR.

	ELISA
		Positive	Negative	Total
PCR	Positive	4	18	22
	Negative	9	24	33
	Total	13	42	55*

*One sample was not available for PCR testing but only for the ELISA test.

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